Physics problems about Joule's law The unit length of a wire is 0.01 Ω / m, which is now used for household circuit power supply. The resistance of the electric furnace at 100m is about 48 Ω. How much heat does the wire generate per minute? If the electric furnace is short circuited, how much heat does the wire generate per second?

Physics problems about Joule's law The unit length of a wire is 0.01 Ω / m, which is now used for household circuit power supply. The resistance of the electric furnace at 100m is about 48 Ω. How much heat does the wire generate per minute? If the electric furnace is short circuited, how much heat does the wire generate per second?

Q=(220/49)2*48*60
Q=(220/1)2*1

A physics problem of Joule's law in Senior High School
Electric lamps L1L2 are respectively "220 V 60 W" and "220 V 40 W" (the picture shows that the two lamps are connected in series to a power supply). 1. No matter how many volts the two terminals are connected, L1L2 can not light normally
2. No matter how many volts the two terminals are connected to, L1 will not glow normally
The answer is 2. I can't figure out why I think L1 can glow normally under a certain high voltage

I think this problem is quite simple
First calculate the resistance of the two
R1=2420/3
R2=2420/2
Because it is in series, the resistance ratio is the voltage value ratio
Therefore, L2 has more voltage than L1
So L2 can reach the rated voltage first, and then L1 can reach it
But then again, when L1 reaches 220 V, what happens to L2?
That is, if L2 exceeds the rated voltage, it will inevitably cause filament burnout!
Therefore, L1 cannot reach the rated voltage!
So two is right and one is wrong